It is known that metformin in the form of hydrochloride is the first choice medicine in the treatment of hyperglycemia and of non-insulin dependent diabetes. This metformin hydrochloride is used alone or in combination with a sulfonylurea, an alpha-amylase inhibitor or a glitazone.
Metformin hydrochloride at the dose of 50 mg/kg in rats is active on conventional models of non-insulin dependent diabetes such as the streptozotocine model and the fructose model.
It has low bioavailability (60%) and its entry through the intestine occurs preferentially in the jejunum and in the ileum. This low bioavailability explains the bothersome side effect of metformin, namely diarrhea.
Metformin is a very basic biguanide which is completely ionized at intestinal pH values. Its entry therefore involves a physiological transporter system, which explains the preferential entry.